Weekend Not Long Enough to Recover From Workweek Sleep Loss

WEDNESDAY June 15, 2011 -- Men and women who get just six hours of sleep each night during the workweek will need more than the weekend to recover from the cumulative effects of this mild sleep deprivation, a new study revealed.

Researchers also found that women are better able to cope with and recover from this kind of sleep loss than men.

"The usual practice of extending sleep during the weekend after a busy workweek associated with mild sleep loss is not adequate in reversing the cumulative effects on cognitive function resulting from this mild sleep deprivation," said the study's principal investigator Dr. Alexandros N. Vgontzas, professor of psychiatry and endowed chair in sleep disorders medicine at the Penn State College of Medicine, in an American Academy of Sleep Medicine news release.

In the study, researchers installed 34 people, with an average age of 25 years and no sleep problems, in a sleep lab for 13 nights. There, they periodically measured sleepiness and performance. Participants were allowed to sleep eight hours a night for the first four nights to assess their typical functioning. For the next six nights, however, they were allowed to sleep only six hours a night, followed by three "recovery" nights of 10 hours of sleep each night.

The study's findings, slated for presentation on Wednesday at Associated Professional Sleep Societies meeting in Minneapolis, revealed that after a week of sleep restriction, two nights of extra sleep are not enough to fully reverse the adverse effects of the sleep loss.

Men and women showed both significantly decreased performance on psychomotor tests, as well as subjective and objective sleepiness.

Women recovered better than men, however, the study pointed out. The researchers said the gender differences were linked to slow wave, or deep sleep, considered the restorative potion of sleep.

"In women, but not in men, deep sleep appeared to have a protective effect," added Vgontzas, who is also director of the Sleep Research and Treatment Center at Penn State in Hershey, Pa. "Women with a higher amount of deep sleep can handle better the effects of one workweek of mild sleep deprivation, and their recovery is more complete after two nights of extended sleep."

More information

The U.S. National Institute of Neurological Disorders and Stroke provides more information on sleep.